The present invention relates to a shift lock system for an automatic transmission of a motor vehicle, and more particularly to a system for preventing the motor vehicle from unexpectedly starting.
In order to prevent the motor vehicle from abruptly starting, a shift lock system is proposed. In the system, an ignition key can not be drawn from an ignition key cylinder in the parking condition of the vehicle, unless a shift lever of the automatic transmission is positioned at a parking (P) range position of the transmission by manipulating the shift lever. In order to select another range other than the P-range for starting the vehicle, a brake pedal must be depressed. Thus, abrupt starting of the vehicle is prevented.
However, the shift lever can be shifted to other positions than the parking position if a shift lever button provided on the shift lever for releasing the lock of the shift lever is depressed after the ignition key is drawn from the key cylinder. Therefore, it is possible to start the engine even if the shift lever is positioned other than in the parking position. This can cause an abrupt starting of the vehicle.